What descriptions about zaroff's physical features serve to warn rainsford (and the reader) about the mans brutal nature?

Physical description:

"Rainsford's first impression was that the man was singularly handsome; his second was that there was an original, almost bizarre quality about the general's face. He was a tall man past middle age, for his hair was a vivid white; but his thick eyebrows and pointed military mustache were as black as the night from which Rainsford had come. His eyes, too, were black and very bright. He had high cheekbones, a sharpcut nose, a spare, dark face--the face of a man used to giving orders, the face of an aristocrat."

_______________________________________________________________

Rainsford was wary of the way Zaroff watched him.

He was finding the general a most thoughtful and affable host, a true cosmopolitan. But there was one small trait of the general's that made Rainsford uncomfortable. Whenever he looked up from his plate he found the general studying him, appraising him narrowly."

_______________________________________________________________

Rainsford was weary of his smile.

"For a moment the general did not reply; he was smiling his curious red-lipped smile."

_______________________________________________________________